Circle attachment for band saws



May 5, 1964 A. JANIAK 'CIRCLE ATTACHMENT FOR BAND sAws Filed July 16,1962 INVENTOR ALEXANDER JANIAK ATTORNEY FIGA FIGC

United States Patent() 3,131,735 CIRCLE ATTACHMENT FOR BAND SAWSAlexander .laniak, 9904 Walnut St., Oakland, Calif. Filed July 16, 1962,Ser. No. 210,038

. 3 Claims. (Cl. 143-26) This invention relates to improvements in meansfor cutting circles and other arcuate forms on conventional band saws inWhich the Work-supporting table can be swung into an angular positionwith respect to a horizontal plane and the invention provides anattachment which is mounted on the head of a band saw and having an armwhich is pivotally connected to the mounting bracket and provided withclamping means, with the arm adjustable in a vertical plane and which isto be adjusted to a planeparallel to the plane of the band saw table toprovide for perpendicular cooperation of the centering pivot with theblank to be cut to form.

This attachment is of the simplest possible construction While providingthe maximum rigidity for ecient operation, the angular adjustment of thearm permittingv the use of rectangular tubular sections for the variousadjustable elements to maintain proper orientation between theadjustable members.

With this invention it is possible to cut discs with the peripheral edgeat right angles to the faces or with the peripheral edge beveled to anydesired angle, and which equally applies to other arcuate forms. j

Furthermore, a universal mounting bracket is provided as standardequipment, and which is secured on a second bracket `which is adapted tothe specific band saw on which it is to be mounted, thus only the secondbracket is varied for the diierent installations.

The objects and advantages of the invention are as follows:

First, to provide a circle attachment for band saws in which thecentering pivot is adjustable to a position perpendicular to the blankfrom which a form is to be cut.

Second, to provide an attachment as outlined inwhich the perpendicularposition of the centering pivot is` obtained through angular adjustmentof the main supporting arm in a vertical plane. v v

Third, to provide an attachment with a main supporting arm which ispivotally mounted in a supporting bracket on a horizontal axis andprovided with clamping means for securing the main supporting arm inadjusted position.

Fourth, to provide a mounting bracket which is adapted to the speciiicband saw on which it is to be mounted and to iixedly attach thesupporting bracket to the mounting bracket for ease of installation andmaintenance of a standard circle attachment construction.

Fifth, to provide an attachment as outlined which is universallyadjustable for thickness of material, angularity of cut, radius of cut,and for relative spacing of the front of the head relative to the pathof the saw blade.

Sixth, to form all elements other than the supporting bracket andcentering pivot housing and clamp of rectangular material for maximumrigidity and maintenance of orientation.

In describing the invention reference will be had to the accompanyingdrawings, in which:

FIG. 1 is a side elevation of the invention and indicating the angularposition for bevel sawing of a disc or the like.

FIG. 2 is a front elevation of the invention.

FIG. 3 is a side elevation of the supporting bracket with clamping meansand the adapter bracket.

FIG. 4 is a front elevation of the clamping means and brackets with thesupporting arm sectioned.

FIG. 5 is an enlarged sectional elevation through the centering pivothousing and showing the pivot.

3,131,735 Patented May 5,v 1964 FIG. 6 is an enlarged top plan View of amodication of the centering pivot arm, with the center-ing pivot armoli-set for deep gaps between the front of the housing and the sawblade.

The invention consists of a supporting arm 10 which is preferably formedof rectangular tubing and which terminates at its inner end in aclamping element consisting of a disc ixed on each side of the arm asindicated at 11 and 12 and having an axial passage formed therethroughfor the clamping bolt 13.

The supporting bracket includes a base 14 which is attachable to themounting bracket 15 as indicated at 16, with the mounting bracketadapted to the speciiic make and model of band saw.

The supporting bracket is provided with a pair of spaced, fairlyextended ears 17 and 18 with the ear 18 having a passage formedtherethrough and in which the clamping screw 13 is rotatable; the otherear having a hub 19 which has a threaded passage for the threaded end 20of the clamping screw, While the other end of the clamping screw has alever 21 fixed thereon, the Iit between the discs 11 and 12 and the ears17 and 18 being normally frictional and thus requiring very littlemovement of the clamping lever 21 for securely clamping the arm in anydesired adjusted position. The arm 10 can be swung into a positionparallel to the work-supporting table and then held in this position byactuating the clamping lever 21.

A sleeve 22 is slidable on the arm and is provided with a clamping screw23 for securing the sleeve in adjusted position, and a second sleeve 23'is ixedly attached at right angles to one side Wall of the rst mentionedsleeve as indicated at 24, this second sleeve also being provided with aclamping screw 25. A drop arm 26 is slidable in this second sleeve andis secured in perpendicular adjustment by the clamping screw 25.

The drop arm 26 terminates at its lower end in a third sleeve which ispositioned at right angles thereto and to the supporting arm, and isalso provided with a clamping screw 27, this sleeve 28 being xed to theend of the drop arm as indicated at 29.

A centering pivot arm 30 is slidable in the third sleeve and releasablysecured by the clamping screw 27, and the centering pivot housing 31 isxed to the terminal end of the centering pivot arm as indicated at 32.For deep gaps it may be necessary to provide the centering pivot armwith a right-angled extension 33, for minimum radii.

The centering pivot includes the housing 31 having an inturned flange 34at its lower end, and a removable cap 35 at the upper end.

'Ihe centering pivot 36 is shown as conically formed and is limited asto projection by an annular collar 37 which froms a part of thecentering pivot and normally seats on the ange 34 and is slidable in thehousing. A Washer 38 is slidable in the housing with the shank 39 of thecentering pivot 36 slidable therein, and a sleeve 40 provides a spacerbetween the washer and the head 35. A compression spring has itsrespective ends seated on the washer and on the annular shoulder 37.This arrangement provides for quick assembly, which consists in thedepression of the sleeve 40 by the cap, followed by screwing the cap onthe housing for placing the spring 41 under suitable tension foreffective securing of the form or blank 42 on the table 43.

FIGURES 1 and 5 show the shank 39 of the centering pin 36, as extendingupwardly through an opening provided in the cap 35 and provided with ahead 44 that is normally spaced above the cap. If the blank 42 that isto be held against the table 43 is a harder wood so that the spring 41will not force the center point 36 into it to the desired extent, theoperator can hit the head 44 with his hand for moving the shank 39downwardly and forcing the center point 36 farther into the blank. Thecentering pin 36 will now hold the blank 42 against the table 43 withsufcient force for preventing transverse movement of the blank withrespect to the center point while permitting the operator to rotate theblank for causing the band saw to make a circular cut in it.

As will be noted by the dotted iigure indicated at 3l' and 36', byadjusting the supporting arm to a plane parallel with the bed or table43 as indicated at 43', an exacting operation can be depended upon sinceal1 inembers are rigidly connected, none of the members being rotatableone relative to the other, with the exception of the centering pivotwhich rotates with the blank.

I claim:

l. A circle attachment for a band saw having an adjustable tableswingable into different angular positions with respect to a horizontalplane, and a head, comprising:

(a) a support arm;

(b) means for pivotally mounting one end of said support arm on saidhead of the band saw, said means permitting said support arm to be swunginto different angular positions about a horizontal axis and in avertical plane and to be held in the desired angular position;

(c) clamping means for securing said support arm in the desired angularposition;

(d a sleeve slidable along said support arm and being manually movableinto a desired position on said arm, said sleeve having a second sleevewhose axis extends at right angles to the axis of the first-mentionedsleeve;

(e) a drop arm slidably mounted in said second sleeve and carrying athird sleeve at its lower end, the axis of said third sleeve extendingat right angles to the axis of said drop arm and to the axis of saidsupport arm;

(f) means for securing said drop arm in adjusted position in said secondsleeve for positioning said third sleeve;

(g) a centering pivot arm slidably mounted in said third sleeve andhaving one end supporting a pivot housing that extends at right anglesto the axis of the centering pivot arm; and

(h) a spring urged centering pivot mounted in said i housing and havinga pivot point projecting from the lower end for centering and securing ablank to said table for cutting an arcuate member therefrom. 2. Astructure as dencd in claim 1, and in which said 5 mounting meanscomprises (a) a base plate having spaced ears projecting at right anglesto the base, and with the supporting arm having a friction disc fixed toeach side wall and frictionally tting between said ears;

(b) a clamp bolt passing through one of said ears, the discs and the armand being threaded into the other of said ears;

(c) said clamp bolt having a lever for manual operation and incombination providing said pivotal mounting and clamping means; and

(d) a mounting bracket having said base plate removably seeured theretoas adapted to the specific band saw to which it is to be attached;

(e) said adjustable table being tiltable into a desired angularposition; and

(f) said support arm being swingable about its supporting means into anangular position Where the longitudinal axis 0f the supporting arm willparallel the plane of the inclined adjustable table.

3. The combination as set forth in claim l, and in which (a) said pivothousing having a guide opening in its top;

(b) said centering pivot having a shank slidably extending through theguide opening in the top of said pivot housing; and

(c) said shank having a head on its upper end that is normally spacedabove the top of said housing;

(d) said head adapted to be manually hit for creating a temporarydownward force on said shank for driving the pivot point of saidcentering pivot down into the blank on said table for holding the blankthereagainst While permitting the blank to be rotated while cutting thearcuate member therefrom.

References Cited in the file of this patent UNITED STATES PATENTS

1. A CIRCLE ATTACHMENT FOR A BAND SAW HAVING AN ADJUSTABLE TABLESWINGABLE INTO DIFFERENT ANGULAR POSITIONS WITH RESPECT TO A HORIZONTALPLANE, AND A HEAD, COMPRISING: (A) A SUPPORT ARM; (B) MEANS FORPIVOTALLY MOUNTING ONE END OF SAID SUPPORT ARM ON SAID HEAD OF THE BANDSAW, SAID MEANS PERMITTING SAID SUPPORT ARM TO BE SWUNG INTO DIFFERENTANGULAR POSITIONS ABOUT A HORIZONTAL AXIS AND IN A VERTICAL PLANE AND TOBE HELD IN THE DESIRED ANGULAR POSITION; (C) CLAMPING MEANS FOR SECURINGSAID SUPPORT ARM IN THE DESIRED ANGULAR POSITION; (D) A SLEEVE SLIDABLEALONG SAID SUPPORT ARM AND BEING MANUALLY MOVABLE INTO A DESIREDPOSITION ON SAID ARM, SAID SLEEVE HAVING A SECOND SLEEVE WHOSE AXISEXTENDS AT RIGHT ANGLES TO THE AXIS OF THE FIRST-MENTIONED SLEEVE; (E) ADROP ARM SLIDABLY MOUNTED IN SAID SECOND SLEEVE AND CARRYING A THIRDSLEEVE AT ITS LOWER END, THE AXIS OF SAID THIRD SLEEVE EXTENDING ATRIGHT ANGLES TO THE AXIS OF SAID DROP ARM AND TO THE AXIS OF SAIDSUPPORT ARM; (F) MEANS FOR SECURING SAID DROP ARM IN ADJUSTED POSITIONIN SAID SECOND SLEEVE FOR POSITIONING SAID THIRD SLEEVE; (G) A CENTERINGPIVOT ARM SLIDABLY MOUNTED IN SAID THIRD SLEEVE AND HAVING ONE ENDSUPPORTING A PIVOT HOUSING THAT EXTENDS AT RIGHT ANGLES TO THE AXIS OFTHE CENTERING PIVOT ARM; AND (H) A SPRING URGED CENTERING PIVOT MOUNTEDIN SAID HOUSING AND HAVING A PIVOT POINT PROJECTING FROM THE LOWER ENDFOR CENTERING AND SECURING A BLANK TO SAID TABLE FOR CUTTING AN ARCUATEMEMBER THEREFROM.